An image may be projected via a projector onto a patterned projection surface or a projection surface with uneven reflectance. In addition, the illumination provided through the projector itself may be uneven or the projection image may be affected by the illumination conditions in the surrounding environment to a significant extent. Under such circumstances, the pattern or the uneven reflectance at the projection surface will be superimposed over the projection image and thus, the projection image cannot be displayed with good fidelity. Patent literature 1 discloses a technology whereby the projection surface onto which a specific projection image is projected is photographed and a projection image is corrected to ensure that the dynamic range of the projection image is set between the maximum value among the smallest brightness values indicated at various pixels of the photographic image within the projection surface and the minimum value among the largest brightness values indicated at the various pixels of the photographic image within the projection surface, so as to cancel out the influence of the pattern and the like and allow the projection image to be displayed with fidelity.
Patent reference 1: Japanese Laid Open Patent Publication No. 2004-158941